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[操作系统]spi子系统之驱动SSD1306 OLED


spi子系统之驱动SSD1306 OLED

 

接触Linux之前,曾以为读源码可以更快的学习软件,于是前几个博客都是一边读源码一边添加注释,甚至精读到每一行代码,实际上效果并不理想,看过之后就忘记了。主要原因是没理解透程序架构,各个模块之间的关系,如何联系在一起,再加上没有实例验证。后来逐渐发现,理解框架能达到事半功倍的效果,理解框架之后,反而代码也更容易看懂,甚至可以猜部分代码的作用,印象更加深刻。

 

理解SPI的驱动框架,还是从最基本的三个入口点触发,platform_device,platform_bus,platform_driver。

 

其中内核一提供给platform_bus,platform_driver在spi_s3c24xx_gpio.c和spi_s3c24xxc.c中,其中spi_s3c24xx_gpio.c用于IO模拟SPI (本例讨论的是IO模拟SPI),spi_s3c24xxc.c用于s3c24xx的硬件SPI。因此,我们需要动手写一个platform_device。

 

看看spi_s3c24xx_gpio.c做了些什么。

 1 static int s3c2410_spigpio_probe(struct platform_device *dev) 2 { 3   ... ... 4   /* [cgw]: 分配一个SPI主机 */ 5   master = spi_alloc_master(&dev->dev, sizeof(struct s3c2410_spigpio)); 6   ... ... 7  8   sp = spi_master_get_devdata(master); 9 10   platform_set_drvdata(dev, sp);11 12   /* [cgw]: 分配与spi硬件相关的配置,如指定哪些IO为MISO,MOSI,SCLK,CS,SPI工作模式,最大时钟等等 */13   /* copy in the plkatform data */14   sp->info = dev->dev.platform_data;15 16   /* [cgw]: 提供实现SPI各种模式的时序的基本方法,和CS的激活方法 */17   /* setup spi bitbang adaptor */18   sp->bitbang.master = spi_master_get(master);19   sp->bitbang.chipselect = s3c2410_spigpio_chipselect;20 21   sp->bitbang.txrx_word[SPI_MODE_0] = s3c2410_spigpio_txrx_mode0;22   sp->bitbang.txrx_word[SPI_MODE_1] = s3c2410_spigpio_txrx_mode1;23   sp->bitbang.txrx_word[SPI_MODE_2] = s3c2410_spigpio_txrx_mode2;24   sp->bitbang.txrx_word[SPI_MODE_3] = s3c2410_spigpio_txrx_mode3;25 26   /* [cgw]: 配置相关io为输入输出 */27   /* set state of spi pins */28   s3c2410_gpio_setpin(sp->info->pin_clk, 0);29   s3c2410_gpio_setpin(sp->info->pin_mosi, 0);30 31   s3c2410_gpio_cfgpin(sp->info->pin_clk, S3C2410_GPIO_OUTPUT);32   s3c2410_gpio_cfgpin(sp->info->pin_mosi, S3C2410_GPIO_OUTPUT);33   s3c2410_gpio_cfgpin(sp->info->pin_miso, S3C2410_GPIO_INPUT);34 35   /* [cgw]: 设置spi的收发,如注册一个工作队列,收发时序的方法,8/16/32的spi数据等等 */36   ret = spi_bitbang_start(&sp->bitbang);37   ... ...38 39   /* [cgw]: 注册sp->info->board_size个spi设备,这几个spi设备都是挂接在统一spi总线上的 */40   /* register the chips to go with the board */41   for (i = 0; i < sp->info->board_size; i++) {42     dev_info(&dev->dev, "registering %p: %s\n",43       &sp->info->board_info[i],44       sp->info->board_info[i].modalias);45 46     sp->info->board_info[i].controller_data = sp;47     spi_new_device(master, sp->info->board_info + i);48   }49   ... ...50 }

 

  1. 注册了一个platform_driver
  2. 在s3c2410_spigpio_probe中,分配并注册了一个spi主机,并注册了挂接在这个SPI主机上的所有spi设备

要想s3c2410_spigpio_probe得到调用,即探测到有效的platform_device,我们需要一个与platform同名("s3c24xx-spi-gpio")的platform_device。

 1 static struct spi_board_info board_info[1] = { 2   { 3   .modalias = "spi_ssd1306",  /* [cgw]: spi设备名,和设备驱动名对应 */ 4   .bus_num = 0,         /* [cgw]: spi总线号,即spi0 */ 5   .chip_select = 2,       /* [cgw]: spi总线上的设备号,即spi0.2 */ 6   .max_speed_hz  = 50000,   /* [cgw]: spi时钟 */ 7   .mode = SPI_MODE_3,      /* [cgw]: spi数据模式 */ 8   }, 9 };10 11 static struct s3c2410_spigpio_info spi_dev = {12   .pin_clk = S3C2410_GPG7,13   .pin_mosi = S3C2410_GPG5,14   .pin_miso = S3C2410_GPG6,15   .board_size = 1,          /* [cgw]: 设置板上spi接口数量为1 */16   .board_info = &board_info[0],17   .chip_select = ssd1306_chip_select18 };19 20 static struct platform_device spi_platform_dev = {21   .name     = "s3c24xx-spi-gpio",    /* [cgw]: 设置平台设备名,和平台驱动名对应 */22   .id      = -1,23   .dev = { 24     .release = spi_dev_release,25     .platform_data = (void *)&spi_dev,   /* [cgw]: 通过platform_data传递spi_dev给平台驱动26                         * 平台驱动可以访问spi_dev27                         */28   },29 };30 31 static int spi_dev_init(void)32 {33   /* [cgw]: 注册spi_platform_dev平台设备 */34   platform_device_register(&spi_platform_dev);35   return 0;36 }

 

spi_bitbang.c提供了spi底层一些实现细节,注册工作队列(SPI数据的传送最终是通过调用工作队列实现的),spi工作模式,工作频率等。

 

 1 int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t) 2 { 3   struct spi_bitbang_cs  *cs = spi->controller_state; 4   u8      bits_per_word; 5   u32      hz; 6  7   if (t) { 8     /* [cgw]: spi驱动指定几位数据模式,和传送速度 */ 9     bits_per_word = t->bits_per_word; 10     hz = t->speed_hz; 11   } else { 12     bits_per_word = 0; 13     hz = 0; 14   } 15  16   /* [cgw]: 根据spi位数,选择合适的时序 */ 17   /* spi_transfer level calls that work per-word */ 18   if (!bits_per_word) 19     bits_per_word = spi->bits_per_word; 20   if (bits_per_word <= 8) 21     cs->txrx_bufs = bitbang_txrx_8; 22   else if (bits_per_word <= 16) 23     cs->txrx_bufs = bitbang_txrx_16; 24   else if (bits_per_word <= 32) 25     cs->txrx_bufs = bitbang_txrx_32; 26   else 27     return -EINVAL; 28  29   /* [cgw]: 设置SCLK的时钟频率 */ 30   /* nsecs = (clock period)/2 */ 31   if (!hz) 32     hz = spi->max_speed_hz; 33   if (hz) { 34     cs->nsecs = (1000000000/2) / hz; 35     if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000)) 36       return -EINVAL; 37   } 38  39   return 0; 40 } 41  42 int spi_bitbang_setup(struct spi_device *spi) 43 { 44   struct spi_bitbang_cs  *cs = spi->controller_state; 45   struct spi_bitbang  *bitbang; 46   int      retval; 47  48   bitbang = spi_master_get_devdata(spi->master); 49  50   /* REVISIT: some systems will want to support devices using lsb-first 51    * bit encodings on the wire. In pure software that would be trivial, 52    * just bitbang_txrx_le_cphaX() routines shifting the other way, and 53    * some hardware controllers also have this support. 54   */ 55   /* [cgw]: 默认不支持LSB模式,要想使用LSB模式,只要bitbang_txrx_le_cphaX()改变移位的方向即可 */ 56   if ((spi->mode & SPI_LSB_FIRST) != 0) 57     return -EINVAL; 58  59   if (!cs) { 60     cs = kzalloc(sizeof *cs, GFP_KERNEL); 61     if (!cs) 62       return -ENOMEM; 63     spi->controller_state = cs; 64   } 65  66   /* [cgw]: 设置spi的默认位数 */ 67   if (!spi->bits_per_word) 68     spi->bits_per_word = 8; 69  70   /* per-word shift register access, in hardware or bitbanging */ 71   /* [cgw]: 设置spi的工作模式,四种 */ 72   cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)]; 73   if (!cs->txrx_word) 74     return -EINVAL; 75  76   /* [cgw]: 调用spi_bitbang_setup_transfer */ 77   retval = bitbang->setup_transfer(spi, NULL); 78   if (retval < 0) 79     return retval; 80  81   dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n", 82       __FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA), 83       spi->bits_per_word, 2 * cs->nsecs); 84  85   /* NOTE we _need_ to call chipselect() early, ideally with adapter 86    * setup, unless the hardware defaults cooperate to avoid confusion 87    * between normal (active low) and inverted chipselects. 88   */ 89  90   /* [cgw]: spi忙的话,通过改变CS的状态释放SPI */ 91   /* deselect chip (low or high) */ 92   spin_lock(&bitbang->lock); 93   if (!bitbang->busy) { 94     bitbang->chipselect(spi, BITBANG_CS_INACTIVE); 95     ndelay(cs->nsecs); 96   } 97   spin_unlock(&bitbang->lock); 98  99   return 0;100 }101 102 103 static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)104 {105   struct spi_bitbang_cs  *cs = spi->controller_state;106   unsigned    nsecs = cs->nsecs;107   108   /* [cgw]: 具体数据收发就是这里实现的 */109   return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);110 }111 112 int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)113 {114   struct spi_bitbang  *bitbang;115   unsigned long    flags;116   int      status = 0;117 118   m->actual_length = 0;119   m->status = -EINPROGRESS;120 121   bitbang = spi_master_get_devdata(spi->master);122 123   spin_lock_irqsave(&bitbang->lock, flags);124   if (!spi->max_speed_hz)125     status = -ENETDOWN;126   else {127     /* [cgw]: 入队一个工作到工作队列 */128     list_add_tail(&m->queue, &bitbang->queue);129     queue_work(bitbang->workqueue, &bitbang->work);130   }131   spin_unlock_irqrestore(&bitbang->lock, flags);132 133   return status;134 }135 136 int spi_bitbang_start(struct spi_bitbang *bitbang)137 {138   int  status;139 140   if (!bitbang->master || !bitbang->chipselect)141     return -EINVAL;142   143   /* [cgw]: 注册一个工作队列 */144   INIT_WORK(&bitbang->work, bitbang_work);145   spin_lock_init(&bitbang->lock);146   INIT_LIST_HEAD(&bitbang->queue);147 148   /* [cgw]: 配置相关方法 */149   if (!bitbang->master->transfer)150     bitbang->master->transfer = spi_bitbang_transfer;151   if (!bitbang->txrx_bufs) {152     bitbang->use_dma = 0;153     bitbang->txrx_bufs = spi_bitbang_bufs;154     if (!bitbang->master->setup) {155       if (!bitbang->setup_transfer)156         bitbang->setup_transfer =157            spi_bitbang_setup_transfer;158       bitbang->master->setup = spi_bitbang_setup;159       bitbang->master->cleanup = spi_bitbang_cleanup;160     }161   } else if (!bitbang->master->setup)162     return -EINVAL;163 164   /* [cgw]: 创建一个单线程,用于调度工作队列 */165   /* this task is the only thing to touch the SPI bits */166   bitbang->busy = 0;167   bitbang->workqueue = create_singlethread_workqueue(168       bitbang->master->cdev.dev->bus_id);169   if (bitbang->workqueue == NULL) {170     status = -EBUSY;171     goto err1;172   }173 174   /* [cgw]: 注册一个spi主机 */175   /* driver may get busy before register() returns, especially176    * if someone registered boardinfo for devices177   */178   status = spi_register_master(bitbang->master);179   if (status < 0)180     goto err2;181 182   return status;183 184 err2:185   destroy_workqueue(bitbang->workqueue);186 err1:187   return status;188 }

 

因为在s3c2410_spigpio_probe中注册了spi的设备,因此我们还需为这些设备提供驱动,以被这些设备探测到,探测这些驱动的条件也是设备和驱动的名字同名,即spi_ssd1306。我们这里提供了一个ssd1306 OLED的驱动

 1 static struct spi_driver spi_ssd1306_driver = { 2   .driver = { 3     .name  = "spi_ssd1306", 4     .bus  = &spi_bus_type, 5     .owner  = THIS_MODULE, 6   }, 7   .probe  = spi_ssd1306_probe, 8   .remove  = __devexit_p(spi_ssd1306_remove), 9 };10 11 static int spi_ssd1306_init(void)12 {13   return spi_register_driver(&spi_ssd1306_driver);14 }

 

到这里,基本工作已经完成。怎样驱动ssd1306 OLED呢?

ssd1306 OLED的使用方法,请参考相关的手册。

本例提供的ssd1306 OLED驱动,只需要我们提供一个基本9位spi数据收发的接口即可。

 

static void ssd1306_write_byte(uint8_t chData, uint8_t chCmd) {  struct spi_transfer t;  struct spi_message m;  uint16_t data = chData;    /* [cgw]: 情况spi_transfer */  memset(&t,0,sizeof(struct spi_transfer));    /* [cgw]: 第9位表示前8位是命令还是数据,1:数据,0:命令 */    if (chCmd) {    data |= (1 << 8);  } else {    data &= ~(1 << 8);  }  /* [cgw]: 要发送的数据 */  t.tx_buf = &data;  /* [cgw]: 长度,2字节 */  t.len = 2;   /* [cgw]: 9位spi */  t.bits_per_word = 9;  //t.cs_change = 1;  /* [cgw]: 把数据添加到收发列表,工作队列调度时会从收发队列中取出,并进行收发   * 注意这里并没有直接收发   */  spi_message_init(&m);  spi_message_add_tail(&t, &m);  spi_sync(spi_ssd1306_dev, &m);}

 

注意,在网上看到一些例子,用8位模式驱动ssd1306 OLED的,需要用DC的状态来表示数据或命令的,他们的做法如下:

 

 1 void ssd1306_write_cmd(uint8_t cmd) 2 { 3   ssd1306_dc_clr(); 4   spi_write(cmd); 5   ssd1306_dc_set(); 6 } 7  8 void ssd1306_write_data(uint8_t data) 9 {10   ssd1306_dc_set();11   spi_write(data);12   ssd1306_dc_clr();13 }

 

 

我本人认为是不正确的,至少不符合这个spi框架的逻辑,因为spi数据的收发并不是直接在spi_write()实现,而是在工作队列bitbang_work()中实现。尽管这样仍然能驱动ssd1306 OLED,但理论上不应该这么做。要改的话应该改bitbang_work()中改,添加DC状态的控制。

 

 

 1 static void bitbang_work(struct work_struct *work) 2 { 3   struct spi_bitbang  *bitbang = 4     container_of(work, struct spi_bitbang, work); 5   unsigned long    flags; 6  7   spin_lock_irqsave(&bitbang->lock, flags); 8   bitbang->busy = 1; 9   /* [cgw]: 队列不为空 */ 10   while (!list_empty(&bitbang->queue)) { 11     struct spi_message  *m; 12     struct spi_device  *spi; 13     unsigned    nsecs; 14     struct spi_transfer  *t = NULL; 15     unsigned    tmp; 16     unsigned    cs_change; 17     int      status; 18     int      (*setup_transfer)(struct spi_device *, 19             struct spi_transfer *); 20  21     /* [cgw]: 取出spi_message */ 22     m = container_of(bitbang->queue.next, struct spi_message, 23         queue); 24     /* [cgw]: 删除这个节点 */ 25     list_del_init(&m->queue); 26     /* [cgw]: 进入临界区 */ 27     spin_unlock_irqrestore(&bitbang->lock, flags); 28  29     /* FIXME this is made-up ... the correct value is known to 30      * word-at-a-time bitbang code, and presumably chipselect() 31      * should enforce these requirements too? 32     */ 33     nsecs = 100; 34  35     spi = m->spi; 36     tmp = 0; 37     cs_change = 1; 38     status = 0; 39     setup_transfer = NULL; 40  41     /* [cgw]: 历遍spi_message中的收发列表 */ 42     list_for_each_entry (t, &m->transfers, transfer_list) { 43  44       /* override or restore speed and wordsize */ 45       /* [cgw]: 如果驱动指定了spi速度,和位数,重新调用spi_bitbang_setup_transfer 46        * 更改默认设置 47       */ 48       if (t->speed_hz || t->bits_per_word) { 49         setup_transfer = bitbang->setup_transfer; 50         if (!setup_transfer) { 51           status = -ENOPROTOOPT; 52           break; 53         } 54       } 55       if (setup_transfer) { 56         status = setup_transfer(spi, t); 57         if (status < 0) 58           break; 59       } 60  61       /* set up default clock polarity, and activate chip; 62        * this implicitly updates clock and spi modes as 63        * previously recorded for this device via setup(). 64        * (and also deselects any other chip that might be 65        * selected ...) 66       */ 67       /* [cgw]: 激活spi */ 68       if (cs_change) { 69         bitbang->chipselect(spi, BITBANG_CS_ACTIVE); 70         ndelay(nsecs); 71       } 72       /* [cgw]: 驱动指定收发完一帧数据要不要改变恢复CS为空闲 */ 73       cs_change = t->cs_change; 74       /* [cgw]: 收发包为空,则无效 */ 75       if (!t->tx_buf && !t->rx_buf && t->len) { 76         status = -EINVAL; 77         break; 78       } 79  80       /* transfer data. the lower level code handles any 81        * new dma mappings it needs. our caller always gave 82        * us dma-safe buffers. 83       */ 84       if (t->len) { 85         /* REVISIT dma API still needs a designated 86          * DMA_ADDR_INVALID; ~0 might be better. 87         */ 88         if (!m->is_dma_mapped) 89           t->rx_dma = t->tx_dma = 0; 90         /* [cgw]: 这里才是真正的实现spi收发时序 */ 91         status = bitbang->txrx_bufs(spi, t); 92       } 93       if (status != t->len) { 94         if (status > 0) 95           status = -EMSGSIZE; 96         break; 97       } 98       m->actual_length += status; 99       status = 0;100 101       /* protocol tweaks before next transfer */102       if (t->delay_usecs)103         udelay(t->delay_usecs);104       105       /* [cgw]: 收发完一帧,不改变CS状态 */106       if (!cs_change)107         continue;108       109       /* [cgw]: 收发列表已经没有数据,结束 */110       if (t->transfer_list.next == &m->transfers)111         break;112 113       /* sometimes a short mid-message deselect of the chip114        * may be needed to terminate a mode or command115       */116       /* [cgw]: 释放spi */117       ndelay(nsecs);118       bitbang->chipselect(spi, BITBANG_CS_INACTIVE);119       ndelay(nsecs);120     }121 122     m->status = status;123     m->complete(m->context);124 125     /* restore speed and wordsize */126     /* [cgw]: 速度和位数恢复默认 */127     if (setup_transfer)128       setup_transfer(spi, NULL);129 130     /* normally deactivate chipselect ... unless no error and131      * cs_change has hinted that the next message will probably132      * be for this chip too.133     */134     if (!(status == 0 && cs_change)) {135       ndelay(nsecs);136       bitbang->chipselect(spi, BITBANG_CS_INACTIVE);137       ndelay(nsecs);138     }139 140     spin_lock_irqsave(&bitbang->lock, flags);141   }142   bitbang->busy = 0;143   /* [cgw]: 退出临界区 */144   spin_unlock_irqrestore(&bitbang->lock, flags);145 }

 

代码:

spi_platform_dev.c

 1 #include <asm/arch/spi-gpio.h> 2  3  4 static struct spi_board_info board_info[1] = { 5   { 6   .modalias = "spi_ssd1306",  /* [cgw]: spi设备名,和设备驱动名对应 */ 7   .bus_num = 0,         /* [cgw]: spi总线号,即spi0 */ 8   .chip_select = 2,       /* [cgw]: spi总线上的设备号,即spi0.2 */ 9   .max_speed_hz  = 50000,   /* [cgw]: spi时钟 */10   .mode = SPI_MODE_3,      /* [cgw]: spi数据模式 */11   },12 };13 14 15 static void ssd1306_chip_select(struct s3c2410_spigpio_info *spi, int cs)16 {17   /* [cgw]: 选中设备号为2的spi设备 */18   if (spi->board_info->chip_select == 2) {19     s3c2410_gpio_cfgpin(S3C2410_GPG2, S3C2410_GPIO_OUTPUT);20     /* [cgw]: 选中设备 */21     if (BITBANG_CS_ACTIVE == cs) {22       s3c2410_gpio_setpin(S3C2410_GPG2, 0);23     /* [cgw]: 释放设备 */24     } else if (BITBANG_CS_INACTIVE == cs) {25       s3c2410_gpio_setpin(S3C2410_GPG2, 1);26     }27   }28 }29 30 /* [cgw]: */31 static struct s3c2410_spigpio_info spi_dev = {32   .pin_clk = S3C2410_GPG7,33   .pin_mosi = S3C2410_GPG5,34   .pin_miso = S3C2410_GPG6,35   .board_size = 1,          /* [cgw]: 设置板上spi接口数量为1 */36   .board_info = &board_info[0],37   .chip_select = ssd1306_chip_select38 };39 40 static void spi_dev_release(struct device * dev)41 {42   printk("spi_dev_release! \n");43 }44 45 /* [cgw]: 分配一个平台设备 */46 static struct platform_device spi_platform_dev = {47   .name     = "s3c24xx-spi-gpio",    /* [cgw]: 设置平台设备名,和平台驱动名对应 */48   .id      = -1,49   .dev = { 50     .release = spi_dev_release,51     .platform_data = (void *)&spi_dev,   /* [cgw]: 通过platform_data传递spi_dev给平台驱动52                         * 平台驱动可以访问spi_dev53                         */54   },55 };56 57 58 static int spi_dev_init(void)59 {60   /* [cgw]: 注册spi_platform_dev平台设备 */61   platform_device_register(&spi_platform_dev);62   return 0;63 }64 65 static void spi_dev_exit(void)66 {67   /* [cgw]: 注销spi_platform_dev平台设备 */68   platform_device_unregister(&spi_platform_dev);69 }70 71 module_init(spi_dev_init);72 module_exit(spi_dev_exit);73 74 MODULE_LICENSE("GPL");


spi_ssd1306_drv.c

 1 #include <linux/init.h> 2 #include <linux/module.h> 3 #include <linux/device.h> 4 #include <linux/interrupt.h> 5 #include <linux/interrupt.h> 6 #include <linux/mtd/mtd.h> 7 #include <linux/mtd/partitions.h> 8 #include <linux/spi/spi.h> 9  10 #define SSD1306_CMD  0 11 #define SSD1306_DAT  1 12  13 #define SSD1306_WIDTH  128 14 #define SSD1306_HEIGHT  64 15  16 static uint8_t s_chDispalyBuffer[128][8]; 17  18 const uint8_t c_chFont1608[95][16] = {    19 {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*" ",0*/ 20 {0x00,0x00,0x00,0x00,0x00,0x00,0x1F,0xCC,0x00,0x0C,0x00,0x00,0x00,0x00,0x00,0x00},/*"!",1*/ 21 {0x00,0x00,0x08,0x00,0x30,0x00,0x60,0x00,0x08,0x00,0x30,0x00,0x60,0x00,0x00,0x00},/*""",2*/ 22 {0x02,0x20,0x03,0xFC,0x1E,0x20,0x02,0x20,0x03,0xFC,0x1E,0x20,0x02,0x20,0x00,0x00},/*"#",3*/ 23 {0x00,0x00,0x0E,0x18,0x11,0x04,0x3F,0xFF,0x10,0x84,0x0C,0x78,0x00,0x00,0x00,0x00},/*"$",4*/ 24 {0x0F,0x00,0x10,0x84,0x0F,0x38,0x00,0xC0,0x07,0x78,0x18,0x84,0x00,0x78,0x00,0x00},/*"%",5*/ 25 {0x00,0x78,0x0F,0x84,0x10,0xC4,0x11,0x24,0x0E,0x98,0x00,0xE4,0x00,0x84,0x00,0x08},/*"&",6*/ 26 {0x08,0x00,0x68,0x00,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"'",7*/ 27 {0x00,0x00,0x00,0x00,0x00,0x00,0x07,0xE0,0x18,0x18,0x20,0x04,0x40,0x02,0x00,0x00},/*"(",8*/ 28 {0x00,0x00,0x40,0x02,0x20,0x04,0x18,0x18,0x07,0xE0,0x00,0x00,0x00,0x00,0x00,0x00},/*")",9*/ 29 {0x02,0x40,0x02,0x40,0x01,0x80,0x0F,0xF0,0x01,0x80,0x02,0x40,0x02,0x40,0x00,0x00},/*"*",10*/ 30 {0x00,0x80,0x00,0x80,0x00,0x80,0x0F,0xF8,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x00},/*"+",11*/ 31 {0x00,0x01,0x00,0x0D,0x00,0x0E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*",",12*/ 32 {0x00,0x00,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80},/*"-",13*/ 33 {0x00,0x00,0x00,0x0C,0x00,0x0C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*".",14*/ 34 {0x00,0x00,0x00,0x06,0x00,0x18,0x00,0x60,0x01,0x80,0x06,0x00,0x18,0x00,0x20,0x00},/*"/",15*/ 35 {0x00,0x00,0x07,0xF0,0x08,0x08,0x10,0x04,0x10,0x04,0x08,0x08,0x07,0xF0,0x00,0x00},/*"0",16*/ 36 {0x00,0x00,0x08,0x04,0x08,0x04,0x1F,0xFC,0x00,0x04,0x00,0x04,0x00,0x00,0x00,0x00},/*"1",17*/ 37 {0x00,0x00,0x0E,0x0C,0x10,0x14,0x10,0x24,0x10,0x44,0x11,0x84,0x0E,0x0C,0x00,0x00},/*"2",18*/ 38 {0x00,0x00,0x0C,0x18,0x10,0x04,0x11,0x04,0x11,0x04,0x12,0x88,0x0C,0x70,0x00,0x00},/*"3",19*/ 39 {0x00,0x00,0x00,0xE0,0x03,0x20,0x04,0x24,0x08,0x24,0x1F,0xFC,0x00,0x24,0x00,0x00},/*"4",20*/ 40 {0x00,0x00,0x1F,0x98,0x10,0x84,0x11,0x04,0x11,0x04,0x10,0x88,0x10,0x70,0x00,0x00},/*"5",21*/ 41 {0x00,0x00,0x07,0xF0,0x08,0x88,0x11,0x04,0x11,0x04,0x18,0x88,0x00,0x70,0x00,0x00},/*"6",22*/ 42 {0x00,0x00,0x1C,0x00,0x10,0x00,0x10,0xFC,0x13,0x00,0x1C,0x00,0x10,0x00,0x00,0x00},/*"7",23*/ 43 {0x00,0x00,0x0E,0x38,0x11,0x44,0x10,0x84,0x10,0x84,0x11,0x44,0x0E,0x38,0x00,0x00},/*"8",24*/ 44 {0x00,0x00,0x07,0x00,0x08,0x8C,0x10,0x44,0x10,0x44,0x08,0x88,0x07,0xF0,0x00,0x00},/*"9",25*/ 45 {0x00,0x00,0x00,0x00,0x00,0x00,0x03,0x0C,0x03,0x0C,0x00,0x00,0x00,0x00,0x00,0x00},/*":",26*/ 46 {0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*";",27*/ 47 {0x00,0x00,0x00,0x80,0x01,0x40,0x02,0x20,0x04,0x10,0x08,0x08,0x10,0x04,0x00,0x00},/*"<",28*/ 48 {0x02,0x20,0x02,0x20,0x02,0x20,0x02,0x20,0x02,0x20,0x02,0x20,0x02,0x20,0x00,0x00},/*"=",29*/ 49 {0x00,0x00,0x10,0x04,0x08,0x08,0x04,0x10,0x02,0x20,0x01,0x40,0x00,0x80,0x00,0x00},/*">",30*/ 50 {0x00,0x00,0x0E,0x00,0x12,0x00,0x10,0x0C,0x10,0x6C,0x10,0x80,0x0F,0x00,0x00,0x00},/*"?",31*/ 51 {0x03,0xE0,0x0C,0x18,0x13,0xE4,0x14,0x24,0x17,0xC4,0x08,0x28,0x07,0xD0,0x00,0x00},/*"@",32*/ 52 {0x00,0x04,0x00,0x3C,0x03,0xC4,0x1C,0x40,0x07,0x40,0x00,0xE4,0x00,0x1C,0x00,0x04},/*"A",33*/ 53 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x11,0x04,0x11,0x04,0x0E,0x88,0x00,0x70,0x00,0x00},/*"B",34*/ 54 {0x03,0xE0,0x0C,0x18,0x10,0x04,0x10,0x04,0x10,0x04,0x10,0x08,0x1C,0x10,0x00,0x00},/*"C",35*/ 55 {0x10,0x04,0x1F,0xFC,0x10,0x04,0x10,0x04,0x10,0x04,0x08,0x08,0x07,0xF0,0x00,0x00},/*"D",36*/ 56 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x11,0x04,0x17,0xC4,0x10,0x04,0x08,0x18,0x00,0x00},/*"E",37*/ 57 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x11,0x00,0x17,0xC0,0x10,0x00,0x08,0x00,0x00,0x00},/*"F",38*/ 58 {0x03,0xE0,0x0C,0x18,0x10,0x04,0x10,0x04,0x10,0x44,0x1C,0x78,0x00,0x40,0x00,0x00},/*"G",39*/ 59 {0x10,0x04,0x1F,0xFC,0x10,0x84,0x00,0x80,0x00,0x80,0x10,0x84,0x1F,0xFC,0x10,0x04},/*"H",40*/ 60 {0x00,0x00,0x10,0x04,0x10,0x04,0x1F,0xFC,0x10,0x04,0x10,0x04,0x00,0x00,0x00,0x00},/*"I",41*/ 61 {0x00,0x03,0x00,0x01,0x10,0x01,0x10,0x01,0x1F,0xFE,0x10,0x00,0x10,0x00,0x00,0x00},/*"J",42*/ 62 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x03,0x80,0x14,0x64,0x18,0x1C,0x10,0x04,0x00,0x00},/*"K",43*/ 63 {0x10,0x04,0x1F,0xFC,0x10,0x04,0x00,0x04,0x00,0x04,0x00,0x04,0x00,0x0C,0x00,0x00},/*"L",44*/ 64 {0x10,0x04,0x1F,0xFC,0x1F,0x00,0x00,0xFC,0x1F,0x00,0x1F,0xFC,0x10,0x04,0x00,0x00},/*"M",45*/ 65 {0x10,0x04,0x1F,0xFC,0x0C,0x04,0x03,0x00,0x00,0xE0,0x10,0x18,0x1F,0xFC,0x10,0x00},/*"N",46*/ 66 {0x07,0xF0,0x08,0x08,0x10,0x04,0x10,0x04,0x10,0x04,0x08,0x08,0x07,0xF0,0x00,0x00},/*"O",47*/ 67 {0x10,0x04,0x1F,0xFC,0x10,0x84,0x10,0x80,0x10,0x80,0x10,0x80,0x0F,0x00,0x00,0x00},/*"P",48*/ 68 {0x07,0xF0,0x08,0x18,0x10,0x24,0x10,0x24,0x10,0x1C,0x08,0x0A,0x07,0xF2,0x00,0x00},/*"Q",49*/ 69 {0x10,0x04,0x1F,0xFC,0x11,0x04,0x11,0x00,0x11,0xC0,0x11,0x30,0x0E,0x0C,0x00,0x04},/*"R",50*/ 70 {0x00,0x00,0x0E,0x1C,0x11,0x04,0x10,0x84,0x10,0x84,0x10,0x44,0x1C,0x38,0x00,0x00},/*"S",51*/ 71 {0x18,0x00,0x10,0x00,0x10,0x04,0x1F,0xFC,0x10,0x04,0x10,0x00,0x18,0x00,0x00,0x00},/*"T",52*/ 72 {0x10,0x00,0x1F,0xF8,0x10,0x04,0x00,0x04,0x00,0x04,0x10,0x04,0x1F,0xF8,0x10,0x00},/*"U",53*/ 73 {0x10,0x00,0x1E,0x00,0x11,0xE0,0x00,0x1C,0x00,0x70,0x13,0x80,0x1C,0x00,0x10,0x00},/*"V",54*/ 74 {0x1F,0xC0,0x10,0x3C,0x00,0xE0,0x1F,0x00,0x00,0xE0,0x10,0x3C,0x1F,0xC0,0x00,0x00},/*"W",55*/ 75 {0x10,0x04,0x18,0x0C,0x16,0x34,0x01,0xC0,0x01,0xC0,0x16,0x34,0x18,0x0C,0x10,0x04},/*"X",56*/ 76 {0x10,0x00,0x1C,0x00,0x13,0x04,0x00,0xFC,0x13,0x04,0x1C,0x00,0x10,0x00,0x00,0x00},/*"Y",57*/ 77 {0x08,0x04,0x10,0x1C,0x10,0x64,0x10,0x84,0x13,0x04,0x1C,0x04,0x10,0x18,0x00,0x00},/*"Z",58*/ 78 {0x00,0x00,0x00,0x00,0x00,0x00,0x7F,0xFE,0x40,0x02,0x40,0x02,0x40,0x02,0x00,0x00},/*"[",59*/ 79 {0x00,0x00,0x30,0x00,0x0C,0x00,0x03,0x80,0x00,0x60,0x00,0x1C,0x00,0x03,0x00,0x00},/*"\",60*/ 80 {0x00,0x00,0x40,0x02,0x40,0x02,0x40,0x02,0x7F,0xFE,0x00,0x00,0x00,0x00,0x00,0x00},/*"]",61*/ 81 {0x00,0x00,0x00,0x00,0x20,0x00,0x40,0x00,0x40,0x00,0x40,0x00,0x20,0x00,0x00,0x00},/*"^",62*/ 82 {0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01,0x00,0x01},/*"_",63*/ 83 {0x00,0x00,0x40,0x00,0x40,0x00,0x20,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"`",64*/ 84 {0x00,0x00,0x00,0x98,0x01,0x24,0x01,0x44,0x01,0x44,0x01,0x44,0x00,0xFC,0x00,0x04},/*"a",65*/ 85 {0x10,0x00,0x1F,0xFC,0x00,0x88,0x01,0x04,0x01,0x04,0x00,0x88,0x00,0x70,0x00,0x00},/*"b",66*/ 86 {0x00,0x00,0x00,0x70,0x00,0x88,0x01,0x04,0x01,0x04,0x01,0x04,0x00,0x88,0x00,0x00},/*"c",67*/ 87 {0x00,0x00,0x00,0x70,0x00,0x88,0x01,0x04,0x01,0x04,0x11,0x08,0x1F,0xFC,0x00,0x04},/*"d",68*/ 88 {0x00,0x00,0x00,0xF8,0x01,0x44,0x01,0x44,0x01,0x44,0x01,0x44,0x00,0xC8,0x00,0x00},/*"e",69*/ 89 {0x00,0x00,0x01,0x04,0x01,0x04,0x0F,0xFC,0x11,0x04,0x11,0x04,0x11,0x00,0x18,0x00},/*"f",70*/ 90 {0x00,0x00,0x00,0xD6,0x01,0x29,0x01,0x29,0x01,0x29,0x01,0xC9,0x01,0x06,0x00,0x00},/*"g",71*/ 91 {0x10,0x04,0x1F,0xFC,0x00,0x84,0x01,0x00,0x01,0x00,0x01,0x04,0x00,0xFC,0x00,0x04},/*"h",72*/ 92 {0x00,0x00,0x01,0x04,0x19,0x04,0x19,0xFC,0x00,0x04,0x00,0x04,0x00,0x00,0x00,0x00},/*"i",73*/ 93 {0x00,0x00,0x00,0x03,0x00,0x01,0x01,0x01,0x19,0x01,0x19,0xFE,0x00,0x00,0x00,0x00},/*"j",74*/ 94 {0x10,0x04,0x1F,0xFC,0x00,0x24,0x00,0x40,0x01,0xB4,0x01,0x0C,0x01,0x04,0x00,0x00},/*"k",75*/ 95 {0x00,0x00,0x10,0x04,0x10,0x04,0x1F,0xFC,0x00,0x04,0x00,0x04,0x00,0x00,0x00,0x00},/*"l",76*/ 96 {0x01,0x04,0x01,0xFC,0x01,0x04,0x01,0x00,0x01,0xFC,0x01,0x04,0x01,0x00,0x00,0xFC},/*"m",77*/ 97 {0x01,0x04,0x01,0xFC,0x00,0x84,0x01,0x00,0x01,0x00,0x01,0x04,0x00,0xFC,0x00,0x04},/*"n",78*/ 98 {0x00,0x00,0x00,0xF8,0x01,0x04,0x01,0x04,0x01,0x04,0x01,0x04,0x00,0xF8,0x00,0x00},/*"o",79*/ 99 {0x01,0x01,0x01,0xFF,0x00,0x85,0x01,0x04,0x01,0x04,0x00,0x88,0x00,0x70,0x00,0x00},/*"p",80*/100 {0x00,0x00,0x00,0x70,0x00,0x88,0x01,0x04,0x01,0x04,0x01,0x05,0x01,0xFF,0x00,0x01},/*"q",81*/101 {0x01,0x04,0x01,0x04,0x01,0xFC,0x00,0x84,0x01,0x04,0x01,0x00,0x01,0x80,0x00,0x00},/*"r",82*/102 {0x00,0x00,0x00,0xCC,0x01,0x24,0x01,0x24,0x01,0x24,0x01,0x24,0x01,0x98,0x00,0x00},/*"s",83*/103 {0x00,0x00,0x01,0x00,0x01,0x00,0x07,0xF8,0x01,0x04,0x01,0x04,0x00,0x00,0x00,0x00},/*"t",84*/104 {0x01,0x00,0x01,0xF8,0x00,0x04,0x00,0x04,0x00,0x04,0x01,0x08,0x01,0xFC,0x00,0x04},/*"u",85*/105 {0x01,0x00,0x01,0x80,0x01,0x70,0x00,0x0C,0x00,0x10,0x01,0x60,0x01,0x80,0x01,0x00},/*"v",86*/106 {0x01,0xF0,0x01,0x0C,0x00,0x30,0x01,0xC0,0x00,0x30,0x01,0x0C,0x01,0xF0,0x01,0x00},/*"w",87*/107 {0x00,0x00,0x01,0x04,0x01,0x8C,0x00,0x74,0x01,0x70,0x01,0x8C,0x01,0x04,0x00,0x00},/*"x",88*/108 {0x01,0x01,0x01,0x81,0x01,0x71,0x00,0x0E,0x00,0x18,0x01,0x60,0x01,0x80,0x01,0x00},/*"y",89*/109 {0x00,0x00,0x01,0x84,0x01,0x0C,0x01,0x34,0x01,0x44,0x01,0x84,0x01,0x0C,0x00,0x00},/*"z",90*/110 {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x3E,0xFC,0x40,0x02,0x40,0x02},/*"{",91*/111 {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00},/*"|",92*/112 {0x00,0x00,0x40,0x02,0x40,0x02,0x3E,0xFC,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"}",93*/113 {0x00,0x00,0x60,0x00,0x80,0x00,0x80,0x00,0x40,0x00,0x40,0x00,0x20,0x00,0x20,0x00},/*"~",94*/114 };115 116 struct spi_device *spi_ssd1306_dev;117 118 static void ssd1306_write_byte(uint8_t chData, uint8_t chCmd) 119 {120   struct spi_transfer t;121   struct spi_message m;122 123   uint16_t data = chData;124   125   memset(&t,0,sizeof(struct spi_transfer));126   127   if (chCmd) {128     data |= (1 << 8);129   } else {130     data &= ~(1 << 8);131   }132 133   t.tx_buf = &data;134   t.len = 2;135   t.bits_per_word = 9;136   //t.cs_change = 1;137   spi_message_init(&m);138   spi_message_add_tail(&t, &m);139   spi_sync(spi_ssd1306_dev, &m);140 }141 142 143 void ssd1306_display_on(void)144 {145   ssd1306_write_byte(0x8D, SSD1306_CMD); 146   ssd1306_write_byte(0x14, SSD1306_CMD); 147   ssd1306_write_byte(0xAF, SSD1306_CMD); 148 }149  150 /**151  * @brief OLED turns off152  *     153  * @param None154  *     155  * @retval None156 **/157 void ssd1306_display_off(void)158 {159   ssd1306_write_byte(0x8D, SSD1306_CMD); 160   ssd1306_write_byte(0x10, SSD1306_CMD); 161   ssd1306_write_byte(0xAE, SSD1306_CMD); 162 }163 164 void ssd1306_refresh_gram(void)165 {166   uint8_t i, j;167   168   for (i = 0; i < 8; i ++) { 169     ssd1306_write_byte(0xB0 + i, SSD1306_CMD);  170     ssd1306_write_byte(0x02, SSD1306_CMD); 171     ssd1306_write_byte(0x10, SSD1306_CMD);   172     for (j = 0; j < 128; j ++) {173       ssd1306_write_byte(s_chDispalyBuffer[j][i], SSD1306_DAT); 174     }175   }  176 }177 178 179 void ssd1306_clear_screen(uint8_t chFill) 180 { 181   memset(s_chDispalyBuffer,chFill, sizeof(s_chDispalyBuffer));182   ssd1306_refresh_gram();183 }184 185 /**186  * @brief Draws a piont on the screen187  *     188  * @param chXpos: Specifies the X position189  * @param chYpos: Specifies the Y position190  * @param chPoint: 0: the point turns off  1: the piont turns on 191  *     192  * @retval None193 **/194 195 void ssd1306_draw_point(uint8_t chXpos, uint8_t chYpos, uint8_t chPoint)196 {197   uint8_t chPos, chBx, chTemp = 0;198   199   if (chXpos > 127 || chYpos > 63) {200     return;201   }202   chPos = 7 - chYpos / 8; // 203   chBx = chYpos % 8;204   chTemp = 1 << (7 - chBx);205   206   if (chPoint) {207     s_chDispalyBuffer[chXpos][chPos] |= chTemp;208     209   } else {210     s_chDispalyBuffer[chXpos][chPos] &= ~chTemp;211   }212 }213    214 /**215  * @brief Fills a rectangle216  *     217  * @param chXpos1: Specifies the X position 1 (X top left position)218  * @param chYpos1: Specifies the Y position 1 (Y top left position)219  * @param chXpos2: Specifies the X position 2 (X bottom right position)220  * @param chYpos3: Specifies the Y position 2 (Y bottom right position)221  *     222  * @retval 223 **/224 225 void ssd1306_fill_screen(uint8_t chXpos1, uint8_t chYpos1, uint8_t chXpos2, uint8_t chYpos2, uint8_t chDot) 226 { 227   uint8_t chXpos, chYpos; 228   229   for (chXpos = chXpos1; chXpos <= chXpos2; chXpos ++) {230     for (chYpos = chYpos1; chYpos <= chYpos2; chYpos ++) {231       ssd1306_draw_point(chXpos, chYpos, chDot);232     }233   }  234   235   ssd1306_refresh_gram();236 }237 238 239 /**240  * @brief Displays one character at the specified position  241  *     242  * @param chXpos: Specifies the X position243  * @param chYpos: Specifies the Y position244  * @param chSize: 245  * @param chMode246  * @retval 247 **/248 void ssd1306_display_char(uint8_t chXpos, uint8_t chYpos, uint8_t chChr, uint8_t chSize, uint8_t chMode)249 {     250   uint8_t i, j;251   uint8_t chTemp, chYpos0 = chYpos;252   253   chChr = chChr - ' ';          254   for (i = 0; i < chSize; i ++) {  255     if (chMode) {256       chTemp = c_chFont1608[chChr][i];257     } else {258       chTemp = ~c_chFont1608[chChr][i];259     }260     261     for (j = 0; j < 8; j ++) {262       if (chTemp & 0x80) {263         ssd1306_draw_point(chXpos, chYpos, 1);264       } else {265         ssd1306_draw_point(chXpos, chYpos, 0);266       }267       chTemp <<= 1;268       chYpos ++;269       270       if ((chYpos - chYpos0) == chSize) {271         chYpos = chYpos0;272         chXpos ++;273         break;274       }275     }    276   } 277 }  278 279 /**280  * @brief Displays a string on the screen281  *     282  * @param chXpos: Specifies the X position283  * @param chYpos: Specifies the Y position284  * @param pchString: Pointer to a string to display on the screen 285  *     286  * @retval None287 **/288 void ssd1306_display_string(uint8_t chXpos, uint8_t chYpos, const uint8_t *pchString, uint8_t chSize, uint8_t chMode)289 {290   while (*pchString != '\0') {    291     if (chXpos > (SSD1306_WIDTH - chSize / 2)) {292       chXpos = 0;293       chYpos += chSize;294       if (chYpos > (SSD1306_HEIGHT - chSize)) {295         chYpos = chXpos = 0;296         ssd1306_clear_screen(0x00);297       }298     }299     300     ssd1306_display_char(chXpos, chYpos, *pchString, chSize, chMode);301     chXpos += chSize / 2;302     pchString ++;303   }304 }305 306 void ssd1306_init(void)307 {308   ssd1306_write_byte(0xAE, SSD1306_CMD);//--turn off oled panel309   ssd1306_write_byte(0x00, SSD1306_CMD);//---set low column address310   ssd1306_write_byte(0x10, SSD1306_CMD);//---set high column address311   ssd1306_write_byte(0x40, SSD1306_CMD);//--set start line address Set Mapping RAM Display Start Line (0x00~0x3F)312   ssd1306_write_byte(0x81, SSD1306_CMD);//--set contrast control register313   ssd1306_write_byte(0xCF, SSD1306_CMD);// Set SEG Output Current Brightness314   ssd1306_write_byte(0xA1, SSD1306_CMD);//--Set SEG/Column Mapping   315   ssd1306_write_byte(0xC0, SSD1306_CMD);//Set COM/Row Scan Direction  316   ssd1306_write_byte(0xA6, SSD1306_CMD);//--set normal display317   ssd1306_write_byte(0xA8, SSD1306_CMD);//--set multiplex ratio(1 to 64)318   ssd1306_write_byte(0x3f, SSD1306_CMD);//--1/64 duty319   ssd1306_write_byte(0xD3, SSD1306_CMD);//-set display offset  Shift Mapping RAM Counter (0x00~0x3F)320   ssd1306_write_byte(0x00, SSD1306_CMD);//-not offset321   ssd1306_write_byte(0xd5, SSD1306_CMD);//--set display clock divide ratio/oscillator frequency322   ssd1306_write_byte(0x80, SSD1306_CMD);//--set divide ratio, Set Clock as 100 Frames/Sec323   ssd1306_write_byte(0xD9, SSD1306_CMD);//--set pre-charge period324   ssd1306_write_byte(0xF1, SSD1306_CMD);//Set Pre-Charge as 15 Clocks & Discharge as 1 Clock325   ssd1306_write_byte(0xDA, SSD1306_CMD);//--set com pins hardware configuration326   ssd1306_write_byte(0x12, SSD1306_CMD);327   ssd1306_write_byte(0xDB, SSD1306_CMD);//--set vcomh328   ssd1306_write_byte(0x40, SSD1306_CMD);//Set VCOM Deselect Level329   ssd1306_write_byte(0x20, SSD1306_CMD);//-Set Page Addressing Mode (0x00/0x01/0x02)330   ssd1306_write_byte(0x02, SSD1306_CMD);//331   ssd1306_write_byte(0x8D, SSD1306_CMD);//--set Charge Pump enable/disable332   ssd1306_write_byte(0x14, SSD1306_CMD);//--set(0x10) disable333   ssd1306_write_byte(0xA4, SSD1306_CMD);// Disable Entire Display On (0xa4/0xa5)334   ssd1306_write_byte(0xA6, SSD1306_CMD);// Disable Inverse Display On (0xa6/a7) 335   ssd1306_write_byte(0xAF, SSD1306_CMD);//--turn on oled panel336 337   ssd1306_display_on();338   ssd1306_clear_screen(0xff);339   340 }341 342 343 static int __devinit spi_ssd1306_probe(struct spi_device *spi)344 {345   printk("spi_ssd1306_probe\n");346   spi_ssd1306_dev = spi;347   spi_ssd1306_dev->bits_per_word = 9;348 349   ssd1306_init();350   ssd1306_clear_screen(0x00);351   ssd1306_display_off();352 353   ssd1306_display_string(18, 0, "hello, Linux!", 16, 1);354   ssd1306_display_string(0, 16, "this is a spi driver demo!", 16, 1);355   ssd1306_refresh_gram();356   ssd1306_display_on();357   358   return 0;359 }360 361 362 static int __devexit spi_ssd1306_remove(struct spi_device *spi)363 {364   printk("ssd1306_remove\n");365   366   ssd1306_clear_screen(0x00);367   ssd1306_display_off();368   return 0;369 }370 371 372 static struct spi_driver spi_ssd1306_driver = {373   .driver = {374     .name  = "spi_ssd1306",375     .bus  = &spi_bus_type,376     .owner  = THIS_MODULE,377   },378   .probe  = spi_ssd1306_probe,379   .remove  = __devexit_p(spi_ssd1306_remove),380 };381 382 383 static int spi_ssd1306_init(void)384 {385   return spi_register_driver(&spi_ssd1306_driver);386 }387 388 389 static void spi_ssd1306_exit(void)390 {391   spi_unregister_driver(&spi_ssd1306_driver);392 }393 394 395 module_init(spi_ssd1306_init);396 module_exit(spi_ssd1306_exit);397 398 MODULE_LICENSE("GPL");

 

makefile

 1 KERN_DIR = /work/system/linux-2.6.22.6 2  3 all: 4   make -C $(KERN_DIR) M=`pwd` modules  5  6 clean: 7   make -C $(KERN_DIR) M=`pwd` modules clean 8   rm -rf modules.order 9 10 obj-m  += spi_platform_dev.o11 obj-m  += spi_s3c24xx_gpio.o12 obj-m  += spi_bitbang.o13 obj-m  += spi_ssd1306_drv.o

 

实验现象: